Field of the Invention
The present invention relates to a trackball input device for a display and, more particularly, to a trackball input device with additional rocking movements.
Description of the Background Art
Trackballs have long been used as input elements for scrolling through lists by restraining the ball's rotation about a given axis. Typically, the horizontal axis is locked for vertical lists and the vertical axis is locked for horizontal lists. Changing the locked axis allows the user to scroll through the type of list shown in the current state of a graphical user interface.
EP 2261773 discloses a conventional trackball mechanism. A depressible navigation trackball is mounted within a socket. The trackball includes a directional positioning mechanism arranged such that the navigation trackball is in communication with the directional positioning mechanism in the depressed configuration. The directional positioning mechanism urges the navigation trackball in one of at least two predetermined directions when the navigation trackball is in the depressed configuration. The trackball allows a user to scroll through a menu and select items in the menu by depressing the trackball.
A conventional trackball, like that disclosed in EP 2261773, has, at most, two distinct mechanical actions when locked on any axis. First, it can rotate about the locked axis (i.e., scrolling motion). Second, it can be depressed (i.e., selecting motion). The user can scroll through lists using the rotation and move further into a hierarchy by pushing down to select.
The conventional trackballs, however, do not have the ability to go back or move out of the hierarchy through a distinct mechanical action. Accordingly, external buttons or specific navigation-relevant list-items must be included in the system to navigate out of the current list. For example, there must be a separate “back” button or a place in the list where the user can choose “back” by using the same down-press to select. The restrained trackball lacks the ability to elegantly navigate through these hierarchies or contexts without needing supplemental input elements or inputs.
Certain conventional designs attempt to circumvent the above problem by allowing selection of the navigation-relevant “back” item within a list (using the down-click/press) and/or having a button separate from the trackball that allows the user to “back.”
There are currently no trackball input devices that allow a user to navigate out of a menu (i.e., go “back”) using only the trackball without additional mechanisms.